PCW flog 'em but I am sure that those who have PCWphobia can buy them from Staples, Office World etc. You can buy the Avery ones or get PCW own brand ones. Setting up the printer is easy as there is usually a template guide included.
I've got a 310, was very fast on PC with ME, on new PC using XP its a bit slow, but it does save having to type labels and fiddle about feeding labels into a printer. I've seen the 310 on offer but I can't remmember where, sorry.